PAM8004 Datasheet, PDF (9/11 Pages) Power Analog Micoelectronics – Filterless 3W Class-D Stereo Audio Amplifier

PAM8004
Filterless 3W Class-D Stereo Audio Amplifier
Application Information
Over Temperature Protection
Thermal protection on the PAM8004 prevents the
device from damage when the internal die
temperature exceeds 140°C. There is a 15 degree
tolerance on this trip point from device to device.
Once the die temperature exceeds the thermal
set point, the device outputs are disabled. This is
not a latched fault. The thermal fault is cleared
once the temperature of the die is reduced by
30°C. This large hysteresis will prevent motor
boating sound well and the device begins normal
operation at this point without external system
intervention.
How to Reduce EMI (Electro Magnetic
Interference)
A simple solution is to put an additional capacitor
1000μF at power supply terminal for power line
coupling if the traces from amplifier to speakers
are short (<20cm).
Most applications require a ferrite bead filter as
shown in Figure 2. The ferrite filter reduces EMI of
around 1 MHz and higher. When selecting a
ferrite bead, choose one with high impedance at
high frequencies, and low impedance at low
frequencies.
OUT+
Ferrite Bead
OUT-
Ferrite Bead
220pF
220pF
Figure 2: Ferrite Bead Filter to reduce EMI
Power Analog Microelectronics,Inc
www.poweranalog.com
9
08/2010 Rev1.0